Roger Federer, Rafael Nadal and Novak Djokovic are collectively called the 'Big 3' for a reason. The trio's respective tallies of 20, 19, and 16 Grand Slam singles titles are the best in the Open Era. It's no surprise that the three of them have also played the most Grand Slam singles finals of any player in tennis history - Federer (31), Nadal (27), Djokovic (25).
Federer made his Grand Slam breakthrough on the grasscourts of Wimbledon in the summer of 2003. Nadal followed suit two years later by winning Roland Garros, and Djokovic won his first Grand Slam title at the Australian Open in 2008.
Since Federer's triumph at 2003 Wimbledon, the Big 3 have won 55 of the next 66 Slams, with only Stan Wawrinka and Andy Murray (three apiece) managing to win multiple Slams during this period. Five other players won a Slam apiece (2003 US Open - Andy Roddick, 2004 French Open - Gaston Gaudio, 2005 Australian Open - Marat Safin, 2009 US Open - Juan Martin Del Potro, and 2014 US Open - Marin Cilic).
No first-time Major winner has emerged since Cilic's Flushing Meadows triumph in 2014. During this period, Federer (3), Nadal (5), and Djokovic (9) have swept 17 of the 20 Slam titles on offer.
The year 2019 ended with Nadal winning his 19th Grand Slam title at the US Open, to trail all-time title leader Federer by just one Slam. The younger players are knocking on the door but not persistently or compellingly enough just yet.
But that could all change as 2019 makes way for 2020.
Stefanos Tsitsipas and Daniil Medvedev are going to be threats at the two hardcourt Majors. Tsitsipas reached his maiden Slam semifinal in Melbourne earlier this year, after ousting two-time defending champion Federer in the fourth round. Medvedev meanwhile continued his glorious North-American summer by reaching a fourth-consecutive title match, which happened to be a Grand Slam.
The young Russian looked down and out at two sets and a break down but fought incredibly well to force a fifth set where he squandered multiple break points before going down to Nadal.
Djokovic is a record seven-time champion at the Australian Open. As has generally been the case over the years, it takes an inspired performance to topple the Serb in Melbourne - a la Wawrinka in 2014.
A triumph at the Australian lays down an early season marker to the rest of the tour. Could one of Tsitsipas, Medvedev, Sascha Zverev or Denis Shapovalov stop the defending champion at the 2020 Australian Open? Perhaps they could.
At Roland Garros, 12-time champion Nadal remains a huge favourite. Dominic Thiem has come close in the last four years, making consecutive semifinals in 2016-17 (lost to Djokovic in 2016 and to Nadal in 2017) and consecutive title matches in 2018-19 (lost both times to Nadal). If Nadal remains fit though, it is hard to see anybody beating the Spaniard at his Paris bastion as he eyes Federer's record tally of 20 Grand Slam titles.
Federer himself would be a threat at Wimbledon. The grasscourt Major is easily Federer's best opportunity to add to his all-time Grand Slam. But at 38, the Swiss is not getting any younger. The courts aren't fast enough and the balls aren't light enough to allow Federer to play a relentlessly attacking game anymore.
Bogged down in baseline rallies, the Swiss can be subdued even at Wimbledon - as Djokovic proved in 2014-15 and 2019, where Federer was not allowed to come to the net as often as he would have liked to.
Coming to the last Grand Slam of the year, the US Open has traditionally been one of the most 'open' Slams. After Federer won the last of his five consecutive Flushing Meadows titles in 2008, no other player has successfully managed to defend his title.
During this span, Del Potro (2009), Murray (2012), Cilic (2014) and Wawrinka (2016) have won their first titles at the tournament. If not at the Australian Open, the US Open is probably the most likely place for one of the non-Big 3 players to make a Slam breakthrough.
Djokovic would remain a threat in 2020, but it appears highly unlikely he will have a three-Slam season a la 2011 or 2015. So for Federer and Nadal, the two all-time leading Grand Slam titlists, it appears 2020 could end 20-20, just as 2019 ended 20-19.
Lets wait and watch as the new season begins in a few weeks' time.